Solidity related question when i change compiler version 0.8 then through error

by using solidity compiler 0.8 through Explicit type conversion not allowed from "address" to "uint256".

for (uint idx = 0; idx < v.length; idx++){
address signer = ecrecover(signedHash, v[idx], r[idx], s[idx]);
require(admins[signer]);
require(uint256(signer) > uint256(lastVoter));
lastVoter = signer;
emit NewCheckpointVote(_sectionIndex, _hash, v[idx], r[idx], s[idx]);

 // Sufficient signatures present, update latest checkpoint. if (idx+1 >= threshold){ hash = _hash; height = block.number; sectionIndex = _sectionIndex; return true; } } // We shouldn't wind up here, reverting un-emits the events revert(); }